COHERENCY TRACKING METHOD AND DATA PROCESSING SYSTEM(ENHANCED COHERENCY TRACKING WITH IMPLEMENTATION OF REGION VICTIM HASH FOR REGION COHERENCE ARRAY)

摘要

PPROBLEM TO BE SOLVED: To provide a method and system for precisely tracking lines evicted from a region coherence array (RCA) without requiring eviction of the lines from a processor's cache hierarchy. PSOLUTION: The RCA is a set-associative array which contains region entries consisting of a region address tag, a set of bits for the region coherence state, and a line-count for tracking the number of region lines cached by the processor. When a region is evicted from the RCA, and lines from the evicted region still reside in the processor's caches (i.e., the region's line-count is non-zero), the RCA line-count is added to the corresponding RVH count. The RVH count is decremented by the value of the region line count following a subsequent processor cache eviction/invalidation of the region previously evicted from the RCA. PCOPYRIGHT: (C)2010,JPO&INPIT